This is one of the places I like to stash out-of-towners when they visit NYC.
They only have a handful of rooms (about a dozen?) and each one is different. The feel of the rooms is homey without being schmaltzy (the bane of B&B's is frilly victorian schmaltz!). It feels more like your own NYC apartment, with some rooms with exposed brick etc.
More homey touches include the life-like butler dummy slouched in his lobby chair and the hotel cat molding his splotchy body to the divans near the registration desk.
There is their site: http://www.innon23rd.com
The New School Culinary Arts Program meets here. They have a fun hands-on kitchen and a big round communal table in the dining room with built-in lazy susan, the better for enjoying the class' outputs. I have never tried the classes, but they look fun and educational, and I hear that other people enjoy the classes very much. More about classes: http://www.nsu.newschool.edu/culinary/